This invention relates to a vacuum pump. In particular, this invention relates to a vacuum pump including a stator disc having a divided structure.
Among vacuum pumps, a Siegbahn molecular pump having a Siegbahn structure has a helical groove (also referred to as a spiral groove or a swirling groove) flow passage on a front surface of at least one of a rotating disc and a stator disc arranged to have a gap (clearance) in the axial direction between the stator disc and the rotating disc, the front surface facing the gap.
Using the rotating disc, a momentum in a direction tangential to the rotating disc (that is, a direction tangential to a rotating direction of the rotating disc) is applied to diffused gas molecules entering the helical groove flow passage, to thereby exhaust the gas molecules with an advantageous directionality from an inlet port to an outlet port, provided by the helical groove.
In Japanese Utility Model Registration No. 2501275, a Siegbahn vacuum pump is described.
In Japanese Patent Application Publication No. 2011-074903, a turbo-molecular pump having the following configuration to reduce the number of components and promote efficiency in assembling is described. At least one stage of a plurality of stages of stator blades includes a plurality of divided stator blades arranged to be in contact with each other in a circumferential direction. The divided stator blades include a plurality of blades juxtaposed in the circumferential direction and an arc-like spacer portion that is connected to an outer periphery of those blades and is configured to position those blades in a predetermined position. As a result, a spacer ring of the related art is not needed.
In Japanese Patent No. 5062257, an inner diameter of the spacer ring is set to be larger than a maximum outer diameter of the stator blade to facilitate stacking of the stator blades and the spacer rings on an outlet port side in order.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the background.